A known example of an anastomotic device comprising two metallic rings suitable to be approached to each other in the axial direction is disclosed in U.S. Pat. No. 4,233,981. The two rings comprise tips suitable to hold in the desired position the pieces of the conduit walls on which the anastomosis is carried out. The two rings further comprise a screw-nutscrew coupling suitable to fasten both rings to each other, such that the pieces of the conduit walls are clamped therebetween.
The known devices, such as that described above, are not without drawbacks.
In fact, they allow obtaining a lumen having a relatively small size as compared with the overall size of the device. Particularly, the operating diameter of the lumen that can be obtained with these known devices has the inner diameter of the rings forming the device as its highest limit.
This entails the disadvantage of having to operate with relatively large-sized devices in order to carry out the anastomosis operation in a successful manner. The use of small-sized devices would in fact allow creating a potentially insufficient lumen with a consequent risk of stenosis which would make the whole anastomosis operation useless.
A lumen with an operating inner diameter being limited by the inner diameter of the rings is particularly uncomfortable when the type of operation employed requires the equipment to be withdrawn through the lumen. In this case, in fact, the edge of the lumen just created may be subjected to stress in order to release the equipment. This stress may be traumatic and generate stenosis or other complications during the operation.
Even if the type of operation does not require any equipment to pass through the lumen, the restraint imposed to the lumen size sensibly affects the effectiveness of the operation, mainly when stenosis or other complications occur.
Accordingly, the need is felt to have an anastomotic device allowing to overcome, at least partially, said the described drawbacks.
The problem at the heart of the present invention is thus to provide an anastomotic device which has such structural and functional characteristics as to meet said requirement.